It was announced in SKE48 Theater, Oya Masana will have her first solo song "Eien no Legacy" in upcoming 21st single (Type-C and Theatre edition), and then she told the fans it will be her graduation song and announced graduation.

Note: Oya Masana is not one of selection members in 21st single.

Oya Masana told the fans she planned it one and half years ago, she also apologized to the fans that she once said she will stay in the group until age 30, but she can not keep her word. She did not reveal her graduation schedule. 



Oya Masana is SKE48 1st generation member, she joined SKE48 in 2018, and officially became Team S member in March 2009. She ranked 22nd in AKB48 General Election 2017.